利用 Ti O2 颗粒与铝合金液原位反应制备了 Al3Ti/ L Y12复合材料 ,采用透射电子显微镜对其微观组织特征进行了研究 ,测试了材料的室温拉伸强度、塑性与冲击韧度 ,并与 L Y12合金进行比较。发现 Ti O2 与 L Y12合金液反应后生成约 4 0 n...利用 Ti O2 颗粒与铝合金液原位反应制备了 Al3Ti/ L Y12复合材料 ,采用透射电子显微镜对其微观组织特征进行了研究 ,测试了材料的室温拉伸强度、塑性与冲击韧度 ,并与 L Y12合金进行比较。发现 Ti O2 与 L Y12合金液反应后生成约 4 0 nm的 Al3Ti颗粒 ,弥散分布在 L Y12基体合金中 ,Al3Ti/ L Y12界面良好结合 ,使复合材料的强度、塑性、冲击韧度均比 L展开更多
The influence of Ti-Si-Mg-AI wire on microstructure and mechanical properties of SiCp/A1 metal matrix composite joints produced by plasma arc in-situ weld-alloying was investigated. Argon-nitrogen mixture was used as ...The influence of Ti-Si-Mg-AI wire on microstructure and mechanical properties of SiCp/A1 metal matrix composite joints produced by plasma arc in-situ weld-alloying was investigated. Argon-nitrogen mixture was used as plasma gas and Ti-Si-Mg-A1 flux-cored wires as filled composites. Weldments were submitted to tensile test. Meanwhile, the macro morphology and microstructure of the joints were examined. The result shows that the formation ofneedie-like harmful phase A14C3 is effectively inhibited and the wettability of molten pool is improved by adding Ti-Si-Mg-A1 flux-cored wires. With 15Ti-5Si-5Mg-A1 flux-cored wire as filled composite, the maximum tensile strength of the welded joint is 267 MPa, which is up to 83% that of the matrix composites under annealed condition.展开更多
The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation...The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation conditions of deformation temperatures of 300−450℃ and strain rates of 0.001^(−1)s^(−1).The results demonstrate that the failure behavior of the composite exhibits both particle fracture and interface debonding at low temperature and high strain rate,and dimple rupture of the matrix at high temperature and low strain rate.Full dynamic recrystallization,which improves the composite formability,occurs under conditions of high temperature(450℃)and low strain rate(0.001 s^(−1));the grain size of the matrix after hot compression was significantly smaller than that of traditional 7075Al and ex-situ particle reinforced 7075Al matrix composite.Based on the flow stress curves,a constitutive model describing the relationship of the flow stress,true strain,strain rate and temperature was proposed.Furthermore,the processing maps based on both the dynamic material modeling(DMM)and modified DMM(MDMM)were established to analyze flow instability domain of the composite and optimize hot forming processing parameters.The optimum processing domain was determined at temperatures of 425−450℃ and strain rates of 0.001−0.01 s^(−1),in which the fine grain microstructure can be gained and particle crack and interface debonding can be avoided.展开更多
An attempt was made to modify the surface of in-situ aluminium matrix composite （AMC） by micro-arc oxidation （MAO）. In the microstructure of AMC, CuAl2 reinforcements were generated by introducing 15% CuO into the...An attempt was made to modify the surface of in-situ aluminium matrix composite （AMC） by micro-arc oxidation （MAO）. In the microstructure of AMC, CuAl2 reinforcements were generated by introducing 15% CuO into the aluminium melt. AMC was hot forged, homogenised, quenched and artificially aged before the MAO in a KOH, KF and Na2SiO3-containing electrolyte. After the MAO process the surface of the AMC was covered with Al2O3 coating having an effective thickness of about 15μm. Appearance of crack and/or delamination free zones at the periphery of the indent after the Rockwell C adhesion test indicated good adhesion between the composite and the Al2O3 coating. During dry sliding wear tests, this adherent Al2O3coating resisted the destructive action of the Al2O3 ball and provided about 15 times enhancement in wear resistance as compared to the original state.展开更多
In-situ 2 vol.%TiB2 particle reinforced Al−xSi−0.3Mg(x=7,9,12,15 wt.%)composites were prepared by the salt−metal reaction,and the microstructures and mechanical properties were investigated.The results show that the T...In-situ 2 vol.%TiB2 particle reinforced Al−xSi−0.3Mg(x=7,9,12,15 wt.%)composites were prepared by the salt−metal reaction,and the microstructures and mechanical properties were investigated.The results show that the TiB2 particles with a diameter of 20−80 nm and the eutectic Si with a length of 1−10μm are the main strengthening phases in the TiB2/Al−xSi−0.3Mg composites.The TiB2 particles promote grain refinement and modify the eutectic Si from needle-like to short-rod shape.However,the strengthening effect of TiB2 particles is weakened as the Si content exceeds the eutectic composition,which can be attributed to the formation of large and irregular primary Si.The axial tensile test results and fractography observations indicate that these composites show more brittle fracture characteristics than the corresponding alloy matrixes.展开更多
文摘利用 Ti O2 颗粒与铝合金液原位反应制备了 Al3Ti/ L Y12复合材料 ,采用透射电子显微镜对其微观组织特征进行了研究 ,测试了材料的室温拉伸强度、塑性与冲击韧度 ,并与 L Y12合金进行比较。发现 Ti O2 与 L Y12合金液反应后生成约 4 0 nm的 Al3Ti颗粒 ,弥散分布在 L Y12基体合金中 ,Al3Ti/ L Y12界面良好结合 ,使复合材料的强度、塑性、冲击韧度均比 L
基金Project (09003) supported by the Open-Fund Research of State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,ChinaProject (JD0805) supported by the Science and Technology Innovation Team,Jiangsu University,China
文摘The influence of Ti-Si-Mg-AI wire on microstructure and mechanical properties of SiCp/A1 metal matrix composite joints produced by plasma arc in-situ weld-alloying was investigated. Argon-nitrogen mixture was used as plasma gas and Ti-Si-Mg-A1 flux-cored wires as filled composites. Weldments were submitted to tensile test. Meanwhile, the macro morphology and microstructure of the joints were examined. The result shows that the formation ofneedie-like harmful phase A14C3 is effectively inhibited and the wettability of molten pool is improved by adding Ti-Si-Mg-A1 flux-cored wires. With 15Ti-5Si-5Mg-A1 flux-cored wire as filled composite, the maximum tensile strength of the welded joint is 267 MPa, which is up to 83% that of the matrix composites under annealed condition.
基金the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2018-ZX04044001-008)the National Natural Science Foundation of China(No.52075328).
文摘The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation conditions of deformation temperatures of 300−450℃ and strain rates of 0.001^(−1)s^(−1).The results demonstrate that the failure behavior of the composite exhibits both particle fracture and interface debonding at low temperature and high strain rate,and dimple rupture of the matrix at high temperature and low strain rate.Full dynamic recrystallization,which improves the composite formability,occurs under conditions of high temperature(450℃)and low strain rate(0.001 s^(−1));the grain size of the matrix after hot compression was significantly smaller than that of traditional 7075Al and ex-situ particle reinforced 7075Al matrix composite.Based on the flow stress curves,a constitutive model describing the relationship of the flow stress,true strain,strain rate and temperature was proposed.Furthermore,the processing maps based on both the dynamic material modeling(DMM)and modified DMM(MDMM)were established to analyze flow instability domain of the composite and optimize hot forming processing parameters.The optimum processing domain was determined at temperatures of 425−450℃ and strain rates of 0.001−0.01 s^(−1),in which the fine grain microstructure can be gained and particle crack and interface debonding can be avoided.
文摘An attempt was made to modify the surface of in-situ aluminium matrix composite （AMC） by micro-arc oxidation （MAO）. In the microstructure of AMC, CuAl2 reinforcements were generated by introducing 15% CuO into the aluminium melt. AMC was hot forged, homogenised, quenched and artificially aged before the MAO in a KOH, KF and Na2SiO3-containing electrolyte. After the MAO process the surface of the AMC was covered with Al2O3 coating having an effective thickness of about 15μm. Appearance of crack and/or delamination free zones at the periphery of the indent after the Rockwell C adhesion test indicated good adhesion between the composite and the Al2O3 coating. During dry sliding wear tests, this adherent Al2O3coating resisted the destructive action of the Al2O3 ball and provided about 15 times enhancement in wear resistance as compared to the original state.
基金The authors are grateful for the financial supports from the National Natural Science Foundation of China(51804349)the China Postdoctoral Science Foundation(2018M632986)the Natural Science Foundation of Hunan Province,China(2019JJ50766).
文摘In-situ 2 vol.%TiB2 particle reinforced Al−xSi−0.3Mg(x=7,9,12,15 wt.%)composites were prepared by the salt−metal reaction,and the microstructures and mechanical properties were investigated.The results show that the TiB2 particles with a diameter of 20−80 nm and the eutectic Si with a length of 1−10μm are the main strengthening phases in the TiB2/Al−xSi−0.3Mg composites.The TiB2 particles promote grain refinement and modify the eutectic Si from needle-like to short-rod shape.However,the strengthening effect of TiB2 particles is weakened as the Si content exceeds the eutectic composition,which can be attributed to the formation of large and irregular primary Si.The axial tensile test results and fractography observations indicate that these composites show more brittle fracture characteristics than the corresponding alloy matrixes.
